Organsniveau

Organsniveau, or the organ level, is a distinct level of biological organization in which groups of tissues come together to form an organ with a specific structure and function. At this level, the arrangement and interaction of multiple tissue types enable complex physiological tasks that individual tissues cannot accomplish alone.

An organ is typically composed of at least two different tissue types that cooperate to perform its function. In animals, this often includes a functional parenchyma and supportive or connective tissue, along with associated vessels, nerves, and sometimes a capsule. In plants, organs such as leaves, roots, stems, and flowers consist of dermal, ground, and vascular tissues arranged to support energy capture, transport, and growth.

Organs arise through specialized developmental processes. In animals, organogenesis proceeds from embryonic germ layers under genetic and molecular control, with signaling pathways guiding tissue differentiation and morphogenesis. In plants, organ formation proceeds through meristem activity and coordinated growth patterns. Throughout life, organs adapt to physiological demands and environmental conditions through changes in size, blood flow, innervation, and cellular activity.

Functions of organs are typically highly integrated within organ systems, enabling coordinated physiology. Examples include the heart pumping blood, the liver processing nutrients and detoxification, and leaves carrying out photosynthesis in plants. Studying the organ level encompasses anatomy, physiology, and histology, and examples such as comparative anatomy highlight variations across species and contexts like organ function, health, and disease.